Thursday, September 17, 2009

NIC Intermittent Connectivity

We have an older desktop provisioned for use by a user with an application which is "less than friendly". So rather than mess with the TS environment we gave her the old desktop. Recently she started having issues with slowness which progressed into lots of messages about Outlook retrieving data, extreme slowdown, network drives dropping offline, and other clients losing connection.

I quickly found in the eventvwr that the tcp/ip connection was going up and down every few minutes. After changing the patch cable and testing the desktop on a new network drop I found the answer. Changing the speed of the NIC from "auto detect" to "100 Mbps Full Duplex" resolved the issue. Apparently in it's old age something started causing it to fail to negotiate the speed. As such it was constantly trying to re-negotiate the speed which caused the up / down connections.